Dissertation Research: Rhizosheath Formation and Hydraulic Lift in Indian Ricegrass: Rhizosphere Composition and Nitrogen Fixation

论文研究：印度稻草的根鞘形成和水力提升：根际组成和固氮

• 批准号: 9212824
• 负责人: Edith Allen
• 金额: $ 0.9万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-12-15 至 1995-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9212824&HistoricalAwards=false
• 关键词: Dissertation; Research; Rhizosheath; Formation; Hydraulic

This study will assess N-fixation in rhizosheath forming and non-rhizosheath forming plants. For the first time. The quantity of nitrogen (N) rhizosheath forming plants obtain from either atmospheric or soil sources will be quantified 15N isotope dilution methods. The function of rhizosheath roots in hydraulic lift will also be measured. Rhizosheath soil may act as sinks for deep soil moisture supplies (hydraulic lift) or rhizosheath roots may act as barriers to moisture loss, which can have a direct effect on microbial activity within rhizosheaths and can significantly alter N-fixation. Research will determine whether hydraulic lift of moisture reserves from deep roots to rhizosheath soil occurs and whether hydraulic lift stimulates microbial numbers and N- fixation in rhizosheaths.

本研究将评估根鞘形成和非根鞘形成植物的固氮作用。这是第一次。根鞘形成植物从大气或土壤中获得的氮量将通过15N同位素稀释法进行量化。还将测量根鞘根在液压升降机中的作用。根鞘土壤可以作为深层土壤水分供应的汇（液压提升）或根鞘根系可以作为水分流失的屏障，这可以直接影响根鞘内的微生物活动，并可以显著改变氮的固定。研究将确定水分储备是否发生从深层根系向根鞘土壤的水力提升，以及水力提升是否会刺激根鞘内的微生物数量和固氮。